In computer networks with a plurality of nodes and a plurality of links linking the nodes to each other, there can be more than one path connecting one node to another. A path from a source or root node to a destination node, can use a first set of links and nodes, or a second set of links and nodes. This situation is similar to other forms of travel, when there are many different routes that one can take from point A to point B. In the interest of efficiency, the different routes are compared and the most optimal route based on the characteristics or metrics of the route is chosen.
As computer networks get larger and larger, and as more people both use the network and find new uses for the network, the amount of traffic on the best links and nodes increases dramatically. When each node desires to communicate with another node, the most optimum path is selected. As a consequence, the nodes and links which have the most optimum metrics, are continuously selected. These nodes and links therefore carry a majority of the network traffic. These most optimum links and nodes consequently easily and rapidly become congested. All this congestion in the nodes can reduce the performance of these nodes, not only in forwarding traffic, but also in their local operations.
Significantly similar paths may exist to the most optimum path where the difference between the most optimum paths and significantly similar paths are minute. However, because the selection of a routing path selects the most optimum path, significantly similar paths are ignored.
As computer networks grow, the possibility of significantly similar routing paths increases. However, these significantly similar routing paths will not be chosen, even if they are minutely less optimal. As a result, increases in traffic due to increases in network size are handled by the same links and nodes and this increases congestion, when the availability of alternate paths due to the increase in network size could reduce congestion.